Advertisement

A Kinetic Investigation of the Mechanisms of Radiation-Induced Strand Breakage in DNA Model Systems

  • George D. D. Jones
  • Peter O’Neill
Conference paper
Part of the NATO ASI Series book series (volume 54)

Abstract

Time-resolved reductions in the light scattering intensity (LSI) of N2O or oxygenated aqueous solutions of single stranded homologous polynucleotides, following pulse irradiation, have been studied as indicies of strand breakage (s.b.) (for a review of the LSI method see Schnabel 1979). With doses of 3–24Gy/pulse, a number of kinetically distinct modes of breakage are apparent. For the polypyrimidines, poly C and poly U, these include i) a small proportion of fast strand breaks (τ½ = 50μs) arising from the direct action of OH-radicals at the sugar phosphate backbone, and ii) major, slower first order routes to breakage that proceed through base radical mediated pathways (Figure 1) (Lemaire et al. 1984).

Keywords

Polymer Degradation Light Scattering Intensity Kinetic Investigation Strand Breakage Radiat Biol 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Reference

  1. Bothe E, Behrens G, Böhm E, Sethuram B, Schulte-Frohlinde D (1986) Hydroxyl radical-induced strand break formation of poly(U) in the presence of oxygen: a comparison of the rates as determined by conductivity, e.s.r. and rapid-mix experiments with a thiol. Int J Radiat Biol 49: 57–66CrossRefGoogle Scholar
  2. Hildenbrand K, Schulte-Frohlinde D (1989) E.s.r. studies on the mechanism of the hydroxyl radical-induced strand breakage of polyuridylic acid. Int J Radiat Biol 55: 725–738PubMedCrossRefGoogle Scholar
  3. Jones GDD, O′Neill P (1990) Kinetics of radiation-induced strand breakage in polynucleotides in the presence of oxygen: a time-resolved light-scattering study. Int J Radiat Biol 57: 1123–1139PubMedCrossRefGoogle Scholar
  4. Lemaire DGE, Bothe E, Schulte-Frohlinde D (1984) Yields of radiation-induced main chain scission of poly U in aqueous solution: strand break formation via base radicals. Int J Radiat Biol 45: 351–358CrossRefGoogle Scholar
  5. Önal AM, Lemaire DGE, Bothe E, Schulte-Frohlinde D (1988) -Y-Rad-iolysis of poly(A) in aqueous solution: efficiency of strand break formation by the primary water radicals. Int J Radiat Biol 53: 87–796CrossRefGoogle Scholar
  6. Schnabel W (1979) Application of the light scattering detection method to problems of polymer degradation. In: Grassie N (ed) Developments in polymer degradation. Applied Science Publishers, London, p 35Google Scholar
  7. Ward JF (1988) DNA damage produced by ionizing radiation in mammalian cells: identities, mechanisms of formation, and repairability. Prog Nucl Acid Res Mol Biol 35: 95–125CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1991

Authors and Affiliations

  • George D. D. Jones
    • 1
  • Peter O’Neill
    • 1
  1. 1.Division of Molecular ProcessesMRC Radiobiology UnitChilton, Didcot, OxonUK

Personalised recommendations